668725818 has 32 divisors (see below), whose sum is σ = 1352604096. Its totient is φ = 220391808.

The previous prime is 668725817. The next prime is 668725847. The reversal of 668725818 is 818527866.

It is not an unprimeable number, because it can be changed into a prime (668725817) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 611280 + ... + 612372.

It is an arithmetic number, because the mean of its divisors is an integer number (42268878).

Almost surely, 2^668725818 is an apocalyptic number.

668725818 is an abundant number, since it is smaller than the sum of its proper divisors (683878278).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

668725818 is a wasteful number, since it uses less digits than its factorization.

668725818 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2158.

The product of its digits is 1290240, while the sum is 51.

The square root of 668725818 is about 25859.7335253092. The cubic root of 668725818 is about 874.4789574934.

The spelling of 668725818 in words is "six hundred sixty-eight million, seven hundred twenty-five thousand, eight hundred eighteen".